JPS625355A - Fluid flow chamber cassette assembly - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to devices and methods for use with fluid flow transfer devices such as dialysis machines.

Fluid flow devices, such as dialysis machines, are used to continuously remove waste products from a patient's blood. Blood is typically pumped through tubing and disposable arterial and venous bubble traps that connect the patient and the dialyzer attached to a dialysate preparation and delivery mechanism.

U.S. Patent No. 4263 to Be11otti et al.
．． No. 808 discloses a monolithic hydraulic circuit with arterial and venous bubble trap chambers as replacement tubing sets, with blood entering through an inlet above the bottom of the bubble trap chamber and exiting near the bottom of the chamber. The pressure inside this bubble trap chamber is
It depends on a transducer pressed into an impermeable latex membrane covering a hole communicating with the upper part of the bubble trap chamber.

According to one feature of the invention, the fluid flow chamber cassette is mounted with either its front wall or its rear wall in contact with the support machine and is provided with a flexible tube. The flexible tube extends from the sidewall and forms a loop. This loop is symmetrical about the loop axis perpendicular to the side walls, so that a pump roller mounted on the machine acts on this loop when the front and rear walls respectively come into contact with the machine. Thus, the orientation of the cassette and the direction of fluid flow through the cassette could be easily adjusted by changing the front or rear walls into or out of contact with the machine.

In a preferred embodiment, one end of the flexible tube is connected to the outlet at the bottom of the chamber, and the other end is connected to the inlet of the channel within the cassette. The distance of this channel entrance from the loop axis is the same as the home exit. The cassette comprises two chambers (arterial chamber and venous chamber) and an additional flexible tube connecting the dialyzer between the flow path and the venous chamber. The outlet of the venous chamber is at the bottom of the venous chamber, and the inlets of the arterial and venous chambers are located above the outlet of their respective chambers. When used with a dialysis machine, blood from the patient flows through an arterial chamber, a symmetrical pump loop and a flow path to the dialyzer, and from the dialyzer back to the patient via a venous chamber.

After dialysis is complete, the cassette and dialysis machine are reversed and reattached to the machine upside down, and the disinfectant is passed through the dialysis machine and cassette in the opposite direction, filling all areas of the cassette, dialysis machine, and tubing. Flow to.

According to another feature of the invention, the arterial chamber inlet is located above the arterial outlet, the venous ventricle inlet is located above the venous nitrogen outlet, and the venous chamber of the fluid flow transfer device is primed by reverse flow. and the initial liquid level and air volume in the venous chambers are automatically kept constant, so that during normal processing of blood, even after reversing the direction of flow, the liquid in the venous and arterial chambers remains constant. It rises to the level of the entrance, so that the air in both chambers remains constant.

According to another feature of the invention, an impermeable flexible diaphragm is placed over the hole in the rigid wall of the fluid flow chamber, a second chamber is provided on the opposite side of the diaphragm, and the pressure in this second chamber is sensed. , the pressure within the fluid flow chamber is sensed.

In a preferred embodiment, the diaphragm is circular and has symmetrically formed corrugated portions, so that the diaphragm hardly stretches (moves) and is sufficiently elastic so that its movement is unrestricted. Sometimes it returns to its original shape.The corrugated section has a semi-circular cross-section, the fluid flow chamber is provided by a cassette removably mounted on the machine fitted with the pressure transducer, and the second chamber is provided with a transducer. A rigid retaining ring formed by the mechanical portion surrounding the vessel and covering the diaphragm is carried by the cassette and has an opening adapted for sealing engagement with the mechanical portion surrounding the transducer.

Other features and advantages of the invention will be apparent from the following detailed description of preferred embodiments of the invention and from the claims.

Referring to FIGS. 1-5, a fluid flow chamber cassette 10 is illustrated that includes tubing for connection to a patient's puncture needle, a blood pump roller, a dialysis machine, and a source of saline and heparin solution. The cassette 10 is made of clear PVC plastic and includes two primary fluid flow chambers, an arterial chamber 14 and a venous chamber 16, in which the blood flows through the inlet tube 18 of the dialysis machine.
And before and after passing through the outlet pipe 20, it flows through these.

The arterial chamber 22 is connected to the arterial inlet 24 and culminates in a narrow vertical inflow channel 26 that enters the arterial chamber 14 through an opening 28 located approximately % above the arterial chamber 14 .

At the bottom of the arterial chamber 14, there is an arterial outlet 5 connected to the flexible tube filter 2.
0, the flexible tube 62 forms a symmetrical loop about the axis 56 and, in use, is squeezed by the rollers of a four-acting pump of a dialysate preparation machine (not shown) to which the cassette 10 is attached. be done.

The other end of the flexible tube 52 is connected to an inlet 64 of a passageway 56 that extends along the top of the cassette 10 and reaches an outlet 68 connected to the inlet tube 18 of the dialysis machine. Heparin port 40 at the top of cassette 10 is connected to heparin tubing 42 and extends into passageway 56.

A saline solution inlet 44 is connected to a saline solution tube 46 and reaches the top of the arterial chamber 14 (FIG. 4).

The dialysis machine tube 20 is connected to an inlet 48 that reaches a narrow vertical inflow channel 49 into the venous chamber 16 at an opening 47 located slightly above the chamber 16 . Venous chamber 16
An outlet 50 of is connected to a conduit arteriosus 52 . Exit 50
A plastic blood filter 54 is provided above.
The flow into this outlet 50 is obstructed. Rubber back frame for sealing 5
Nine access holes 56,58 are formed in the front wall of the arterial chamber 14 and the venous chamber 16. The needle guard 61 prevents the needle inserted into the stopper 59 from entering the chambers 14 and 16.

Referring to FIG. 2 and FIGS. 6-8B, back plate 98
comprises a hole 60,62 in the arterial chamber 14, and the venous chamber 16 comprises:
Diaphragms 64., which are identical except that their orientation is reversed.
covered by 66. The diaphragm 64, which receives negative pressure within the arterial chamber 14, has its semicircular corrugated portion 80 extending from the arterial chamber 14, and the diaphragm 66, which receives positive pressure within the arterial chamber 14, has its semicircular corrugated portion 80 extending from the arterial chamber 14. extends into the arterial chamber 14. During use (FIG. 6), the diaphragm retaining ring 68,70, which is provided with a cylindrical through passage 71 into which the cylindrical extension body 82 of the pressure sensor 85 attached to the surface of the machine to which the cassette 10a' is connected, is inserted is attached to the diaphragm 64. It is provided on the rear side of .66. At the periphery of the diaphragm 64.66 there is an annular surface 74.76 of the retaining ring 68.70 and an annular opposing surface 7 surrounding the holes 60, 62.
A bead portion 72 that is narrowed between 8 is formed. The end edge 96 of the diaphragm 64.66 is squeezed between the lip piece 66 of the retaining ring 6B, 70 and the opposing lip piece 65 surrounding the hole 60.62, so that there is a gap between the diaphragm and the retaining ring and between the diaphragm and the back plate. Form a sealing device.

Referring to FIG. 6, the elongated body 82 includes an O-ring 84 that forms a seal against the inner surface of the cylindrical passageway 71. Pressure transducer element 85 is exposed to chamber 57, which includes the volume within wall 86, passageway 8B (formed in extension 82) and the area between the inner surface of retaining ring 6B and diaphragm 64. The same pressure sensor engages the inner surface of the cylindrical passage 71 of the retaining ring 70.

A semicircular corrugated portion 80 extends along the diaphragm 64 and has an outer surface radius of 0.125 inches.
It extends 180° around its center. The opposite surface of the upper ring 68 has the same radius, but is not completely unilateral around the center.
Not extended by 80°, above the central portion 90 of the diaphragm 64 o, o6
It terminates at surface 89 located at s inches (approximately 1.65 mm). On the opposite side of the septum 64, 66 there are four radial protrusions 92 which have the effect of preventing occlusion of the passageway 8B in the septum 66 within the venous chamber. The thickness of the semicircular portion 80 of the diaphragm 64 is o and oi.
o inch (approximately 0.254 mm ), and the thickness of the center portion 90 and the edge portion 96 adjacent to the bead portion 72 is 0.02 mm.
0 inch (approximately 0.508 mm). The diaphragm 64 is made of silicone rubber (Dow Cornin
g) available under the trade name MDX4-4515) and is non-toxic. The corrugated portion 80 can be transferred in either direction without stretching or friction, and is sufficiently elastic to return to its original shape unless movement is restricted by fluid conditions within the chamber. can do.

As shown in FIG. 4, the cassette 10 is primarily composed of two PvC molded pieces, a flat back plate, and a front piece 100, with holes and walls formed for a number of chambers and passageways. The back plate 98 is connected to the front piece 100 by solvent adhesive. Similarly, the retaining ring 68 is attached to the back plate 9.
8 with solvent adhesive.

In operation, the cassette 10 is connected to the dialysate dispensing device (Fig. (not shown). When the back plate 98 of the cassette 10 contacts the machine and is locked in place, the extension 8 of the machine's pressure sensor
2 is automatically fitted into the cylindrical passage 71 of the retaining ring 68 and sealed by the O-ring 84. The loop tube 62 is
Fitted around the rollers of a peristaltic pump (not shown) carried at the front of the machine, the axis of the blood pump is perpendicular to the axis of the annulus.

Referring to FIG. 1, the direction of flow during dialysis is indicated by solid arrows, and the direction of flow during priming is indicated by open arrows. Before use on a patient, the cassette 10, the various tubes 52 and the hollow fiber dialysis device connected to these tubes are assembled by connecting the ends of the various tubes 52 to the saline bag and turning the pump acting on the tube 62 with the open arrow. Operate in the direction shown (clockwise) and prime with saline solution. This draws saline solution into the venous chamber 16. Venous chamber 1
The amount of liquid in 6 is automatically determined by the height of opening 47 at the end of inlet passage 49 from inlet 48. After the saline solution reaches the level of opening 47, the fluid volume and air volume within venous chamber 16 remains unchanged. However, when initially filling the venous chamber, the pump should be operated at a slightly higher speed than the normal speed and the liquid level should be slightly higher than the opening 47 to prevent air bubbles from being carried to the dialysis machine during priming. I can. The fluid level of the arterial chamber 14 is automatically set by the height of the opening 28. Then, the saline solution flows through the intravenous tube 22Y. After completely removing the air from the dialysis machine, connect the arterial tube to the needle that is punctured and closed in the patient.

The dialysis machine does not need to be reversed after priming, as is commonly done in the past. Also, the arterial chamber 14. Since the level of the liquid in the venous chamber 16 is determined naturally, priming is much quieter, easier to operate, and more reliable than the time-consuming priming that requires manual level adjustment using a conventional blood tube set. It can be performed.

A heparin source is connected to tube 42 and a saline solution source is connected to tube 46. Heparin is automatically supplied to flow path 56 to prevent blood clots within the dialysis machine. Because the flow path 36 is under positive pressure, heparin is not drawn into the dialysis machine faster than necessary. The saline solution tube 46 is maintained occluded and acts as an emergency means to quickly administer fluids to the patient in the event of shock.

The blood pump 28 is then actuated in a forward (counterclockwise) direction to draw the patient's blood into the tube 22, the flow path of the cassette 10, and the associated tubes, and to drain the saline solution from the end of the tube 52. and replace it with blood. Once the dialyzer and associated tubing are filled with blood, the blood pump is stopped. The end of the intravenous line 18 is connected to the patient's insertion needle and the pump is activated counterclockwise to begin dialysis, causing blood to flow in the direction indicated by the solid arrow.

During dialysis, arterial chamber 14. The amount of air within the venous chamber 16 is maintained constant. A pressure sensor 86, isolated from the blood flow path by a non-toxic diaphragm 64,64, monitors the pressure. The arterial chamber 14 has an overall negative pressure (approximately -150 mmHg), and the venous chamber 16 has an overall positive pressure (approximately +350 mmHg).
9). The air volume within the compartments 14,16 can be adapted to pressure fluctuations caused by the operation of the peristaltic pump.

As the pump operation direction changes, the pressure switches between positive and negative pressure, so the fluid level in the arterial chamber 14 is slightly lower than during priming, and the fluid level in the venous chamber 16 is slightly lower than during priming. The septum 64 moves into the arterial chamber 14 without stretching or friction (due to the presence of the corrugations 80) and balances the pressure in the chamber 87 with the pressure in the arterial chamber 14. The septum 66 also Similarly, without stretching or friction, the corrugated portion 80 rolls toward the retaining ring 70 to balance the pressure in the chamber associated with its transducer and the pressure in the venous chamber 16.

After dialysis, tubing 22 is removed from the patient and connected to a source of saline solution, allowing the blood in the hydraulic circuit to return to the patient. Heparin tubing 42 and saline solution tubing 46 are removed from their respective sources and interconnected. The cassette 10 and associated dialysis machine 7 are then reversed so that the front of the cassette 10 is in contact with the machine, with the outlet 60 at the top and the inlet 34 at the bottom. The pump is then driven clockwise to draw disinfectant into the tubes 22 and into the system, ensuring that the disinfectant reaches all areas of the circuit. The arterial line 22 and the venous line 52 are interconnected to supply the cassette and dialysis machine with a saline solution, and to drain the saline solution before reuse on the patient.

Other embodiments of the invention are also within the scope of the invention.

For example, Fig. 9 shows a case (11) used for single-needle dialysis.
0a' is shown. Arterial chamber 116 inlet 149 and venous chamber 11
4. The inlet 128 is provided at the bottom (the inlet 149 is located about a point above the bottom, and the inlet 128 is located about 1/2 above the bottom).
, the air volume is increased (and during the arterial and venous phases, small pressure changes allow the fluid volume to change).

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional plan schematic illustration of a cassette for use with a fluid flow transfer device in accordance with the present invention; FIG. 2 is a schematic rear perspective view of the cassette of FIG. 1, shown as a partially exploded view; FIG. The front perspective view of the cassette in FIG. 1 and FIG.
1. FIG. 5 is a partial vertical sectional view of the cassette in FIG. 1 along line 4--5. FIG. 6 is a partial longitudinal sectional view of the cassette in FIG. Figure 1 shows the pressure sensing part of the cassette connected to the pressure sensor;
FIG. 7 shows another pressure sensing portion of the FIG. 1 cassette;
A partial cross-sectional view taken along line 7--7 in FIG.
FIG. 9 is a partially exploded sectional view of the pressure sensing portion, and FIG. 9 is a partially sectional plan view of a cassette in another embodiment according to the present invention. (Explanation of main symbols)

Claims (1)

[Claims] 1. A fluid flow chamber cassette assembly for mounting on a machine comprising a peristaltic pump roller moving about the pump axis and a support means for a fluid flow transfer device, the fluid flow chamber cassette assembly being spaced apart from each other. a plastic casing having a front wall and a rear wall coordinating with each other and a side wall forming a first fluid flow chamber on one side between the front wall and the rear wall; the casing having a chamber inlet and a first chamber outlet of the first fluid flow chamber formed in the side wall; for flowing liquid from the first fluid flow chamber to the transfer device; a first flexible tube forming part of a loop operable;
An end is connected to the first chamber outlet, and another portion of the loop is fixed to the casing, so that the loop is symmetrical about a loop axis that intersects the side wall, and the loop axis is , the first flexible tube passing through the pump axis when attached to the machine; the casing being in contact with the machine; the first flexible tube being in contact with the machine; mounting means attachable to the machine at two mounting locations; a second location being the front wall of the loop; Said second
a fluid flow chamber cassette assembly, wherein the fluid flow chamber cassette assembly is configured to be opposite to each other with respect to the loop axis when the fluid flow chamber cassette assembly changes to the position shown in FIG. 2. When the cassette assembly is installed on the machine, the loop axis is in a horizontal position, and when the rear wall is installed on the machine, the first chamber outlet is at the bottom of the first fluid flow chamber. and the first chamber outlet is located at the top of the first fluid flow chamber when the front wall is attached to the machine. Fluid flow chamber cassette assembly. 3. The cassette assembly has a flow path, a flow path inlet spaced equidistant from the loop from the first chamber inlet, and a second flexible tube that connects to a fluid flow transfer device. 2. The fluid flow chamber cassette assembly according to claim 1, further comprising a flow path outlet and a flow path inlet connected to said first flexible tube. 4. the cassette assembly comprising a second fluid flow chamber having a second chamber inlet and a second chamber outlet; a third flexible chamber connecting the second chamber inlet to the fluid flow transfer device; 4. A fluid flow chamber cassette assembly according to claim 3, wherein the fluid flow chamber cassette assembly is adapted to be connected to a pipe. 5. The cassette assembly comprises a first access port to the first fluid flow chamber and a second access port to the flow path.
The fluid flow chamber cassette assembly described in Section. 6. When the cassette assembly is installed on the machine, the loop axis is in a horizontal position, and when the rear wall is installed on the machine, the first chamber outlet is at the bottom of the first fluid flow chamber. the first chamber outlet is at the top of the first fluid flow chamber when the front wall is attached to the machine, and the second chamber outlet is at the top of the first fluid flow chamber when the front wall is attached to the machine; The chamber outlet is at the bottom of the second fluid flow chamber, and when the front wall is attached to the machine, the second chamber outlet is at the top of the second fluid flow chamber. A fluid flow chamber cassette assembly according to claim 4. 7. The first inlet of the first fluid flow chamber is located above the first outlet when the rear wall is attached to the machine. A fluid flow chamber cassette assembly as described in paragraph 6. 8. The second inlet of the second fluid flow chamber is located above the second outlet when the rear wall is attached to the machine. Fluid flow chamber cassette assembly as described in paragraph 7. 9. The attachment means comprises a tubular protrusion extending from the side wall about an axis parallel to the axis of the loop and providing the first outlet and the channel inlet. A fluid flow chamber cassette assembly according to claim 3. 10. The fluid flow chamber cassette assembly of claim 9, wherein said attachment means further comprises a protrusion extending from said cassette assembly opposite said sidewall. 11. The first inlet to the first fluid flow chamber is approximately 1.1 mm above the chamber when the rear wall is in contact with the machine.
8. The fluid flow chamber cassette assembly according to claim 7, wherein the fluid flow chamber cassette assembly is located at the /2 position. 12. The first inlet to the first fluid flow chamber is located approximately 2.5 mm above the chamber when the rear wall is in contact with the machine.
8. The fluid flow chamber cassette assembly according to claim 7, wherein the fluid flow chamber cassette assembly is located at the /3 position. 13. said second inlet to said second fluid flow chamber is approximately 1.5 m above said chamber when said rear wall is in contact with said machine;
9. The fluid flow chamber cassette assembly according to claim 8, wherein the fluid flow chamber cassette assembly is located at the /2 position. 14. Claim 8, wherein the inlet of the second fluid flow chamber is located approximately 1/4 above the chamber when the rear wall is in contact with the machine. The fluid flow chamber cassette assembly described in . 15. A fluid transfer device connected to the second flexible tube and the third flexible tube, and a peristaltic pump roller, means for engaging the attachment means, and supporting the fluid flow transfer device in two positions. one of said two positions is a position where said flow path inlet is at the top and said first outlet is at a bottom; 5. The fluid flow chamber cassette assembly according to claim 4, wherein the flow path inlet is at the bottom and the first outlet is at the top. 16. providing a fluid flow transfer device, an arterial chamber, and a venous chamber, connecting an inlet of the fluid flow transfer device to an outlet of the arterial chamber, and connecting the outlet of the fluid flow transfer device to the inlet of the transfer device; an inlet connected to the inlet of the venous chamber, the inlet entering the arterial chamber at a position above the outlet of the arterial chamber, the inlet of the venous chamber at a position above the outlet of the venous chamber; through the venous chamber, the fluid flow transfer device and the arterial chamber;
in a direction opposite to the normal operating direction of said device, i.e.
Prime the blood flow path of the device by delivering a sterile priming solution into the outlet of the venous chamber, thus raising the sterile solution within the venous chamber to the level of the venous chamber inlet and causing the internal The fluid flows upwardly through the arterial chamber while removing air bubbles and reaches the arterial chamber, raising the fluid level in the arterial chamber to the level of the inlet of the arterial chamber, thus and automatically maintaining an initial fluid level and air volume within a venous chamber at a predetermined height and volume. 17. further connecting the inlet of the arterial chamber to the patient until the sterile solution in the device is replaced with blood;
delivering in a direction opposite to that during priming; and connecting an outlet of the venous chamber to the patient;
and continuing delivery in the same direction to effect a transition within the device. 18. The method of claim 17, further comprising sensing pressure within the arterial and venous chambers during the successive delivery steps. 19. further comprising connecting the inlet of the arterial chamber to a sterile solution, pumping blood back into the patient, disconnecting the patient, and inverting the device and the arterial and venous chambers. and delivering a sterilizing solution through the venous chamber outlet and the entire area within the flow path of the device. How it works. 20, an inlet and an outlet for the liquid flowing therein;
a first chamber having a rigid wall having a through opening; an impermeable flexible septum sealably covering the through opening; and an impermeable flexible septum opposite the septum from the first chamber having the rigid wall; means for forming a second chamber hermetically sealed in the second chamber, and means communicating with the second chamber for detecting the internal pressure thereof;
A liquid pressure sensing device comprising: a pressure transducer that deflects the diaphragm and changes the volume and pressure inside the second chamber according to a change in the pressure inside the chamber. 21. The diaphragm is circular and includes symmetrically formed corrugated portions, the diaphragm moves with little stretching, the diaphragm further has sufficient rigidity, and the diaphragm has sufficient rigidity to prevent fluid in the first and second chambers. 21. The pressure sensing device according to claim 20, wherein the pressure sensing device is configured to return to its original shape when its movement is not restricted depending on the state. 22. The pressure sensing device according to claim 21, wherein the waveform portion has a semicircular cross-sectional shape. 23. said first chamber being provided by a cassette removably attached to said machine, said means for attaching said pressure transducer to said machine, and said means for forming a second chamber being attached to said machine; a portion surrounding the transducer and a rigid retaining ring covering the diaphragm, the diaphragm being carried by the cassette and sealingly engaging the portion surrounding the transducer; 21. The pressure sensing device according to claim 20, characterized in that the pressure sensing device is provided with an opening. 24. Claim 23, characterized in that the opening is formed by a cylindrical passage that fits into a cylindrical projection that includes a pressure sensor passage to the auxiliary chamber provided with the transducer. Pressure sensing device described in section. 25. The pressure sensing device according to claim 23, wherein the retaining ring has an inner surface having the same shape as the corrugated portion. 26. The pressure sensing device according to claim 24, wherein the diaphragm includes a rib that comes into contact with the cylindrical protrusion and prevents the passage of the pressure sensor from being blocked.